Exploits in diablo 2 are going to completely change how it is to play the game. Here are some major examples of d3 exploit:
The first would have to be a pvp exploit. So maybe you have a way to combine some rare runes and items to have an instant kill on opponents. Or a way to bug out some life steal so that you cant die when you are doing duels with other players.
Another would have to be boss fights. Lets say you are fighting diablo in the game. Well using an exploit that makes him sit there and not attack is a major exploit that gives you a giant advantage over other players when it comes to farming end game bosses.
Finally it would have to be a auction house exploit. Trading is going to be big and if you have a way to list items with making them seem like something else you can exploit it. A good way people did that in other games was showing someone an items stats. Then opening up a trade and swapping the item. Once they hit trade you can at times scam them from the items. It worked very well and people will be doing it in diablo 3.
